With the development of medical image processing technique and three-dimensional visualization technique, image processing technique including virtual endoscopy, a technique for unfolding a cavity wall of an organ, etc. may be applied widely with significant advantages of non-invasion, repeatability, etc. The virtual endoscopy technique may be mainly used in one or more organs with a cavity tissue structure, such as a colon, a trachea, a blood vessel, an inner ear, etc. For example, the virtual endoscopy may offer a minimally invasive colonoscopy way. Thus, one or more intestinal polyps may be detected in advance, and an occurrence of colon cancer may be prevented. The technique for unfolding a cavity wall of an organ may be mainly used for converting a three dimensional (3D) view of a cavity wall to a two dimensional (2D) plane view thereof, so as to facilitate observing and comparing one or more tissues inside the cavity wall, finding a pathological tissue and displaying it, thereby benefiting subsequent diagnosis and treatment. For example, the technique for unfolding a cavity wall of an organ may offer a way for unfolding an intestinal wall into a 2D plane view.